I'm an electronics engineer, I have primary only worked with digital and analog design, never with RF design. But finding the field interesting, I wanted to do a project mainly to get better RF design skills. So I decided to build a simple spectrum analyzer, using a PLL with integrated VCO, a mixer and some matching circuits. The signal to analyze is feed into the mixers RF port, the PLL(VCO) generates the LO signal for the mixer, and by filtering the IF output signal and measuring the power from DC to some frequency, I should be able to get the frequency content at the LO frequency. The PLL(VCO) frequency is set using a MCU, so the idea is to just set the frequencies of interest, and measure the power at the mixer IF port from DC to some frequency.
Hope that makes sense. :-)
Now how do I measure the power in the IF signal, from say DC to 10KHz?